The purpose of this project is to study the interaction of normal and metastatic tumor cells with components of the extracellular matrix. Specific emphasis has been placed on understanding metastatic tumor cell usage of laminin, various laminin fragments and the laminin receptor in cell adhesion to basement membrane. Additional studies have included the examination of directed migration of metastatic tumor cells to target organ specific factors. These studies have been termed "chemoinvasion" (chemo from chemotaxis and invasion from the cells ability to invade an artifical basement membrane barrier). Using the artificial basement membrane barrier various tumor cells have beem selected for their ability to invade and migrate. These cells show increased metastatic propensity. Further studies have utilized laminin and fibronectin to modulate of the invasive potential of tumor cells. Laminin increases, while fibronectin decreases invasiveness. A second direction of this project involves laminin and fibronectin in conjunction with tooth root preparation as a mean to stimulate periodontal reattachment. Various root preparations are being considered.